Nucleolar PARP-1 Expression Is Decreased in Alzheimer’s Disease: Consequences for Epigenetic Regulation of rDNA and Cognition

Figure 2

PARP-1 nucleolar immunoreactivity is altered in hippocampal pyramidal cells in AD brains. Representative confocal microscopy of PARP-1 immunostaining (red) with DAPI nuclear counterstaining (blue) of CA4 hippocampal pyramidal neurons. In controls brains (a–c) a high percentage of pyramidal cell nucleoli have intense and well- delineated PARP-1 staining (arrowheads). In contrast, in AD brains (d–f), the percentage of intensely stained and well-delineated nucleoli is less than in the controls and there is a more dispersed pattern with weak label intensity ((d) and (f), arrow). ((g) and (h)) The percentage of CA1 (g) and CA4 (h) hippocampal pyramidal neurons with PARP-1 positive nucleoli staining was less in AD cases compared to controls. (Control, and for CA1 and CA4, resp.; AD, for both CA1 and CA4; .) Scale bar = 25 μM.

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